Dishwasher

ABSTRACT

A dishwasher is provided. The dishwasher measures the amount of vibration caused by a drain pump, and terminates the operation of the drain pump if the amount of vibration measured exceeds a predefined vibration level. Thus, it is possible to precisely determine, during a drain operation, when a sump will be completely drained and thus prevent the drain pump from being driven any longer if no wash fluid remains in the sump. Therefore, it is possible to prevent excessive vibration and noise from being generated.

This application claims priority to Korean Patent Application No. 10-2007-0088505 filed in Korea on Aug. 31, 2007, the entirety of which is incorporated herein by reference.

BACKGROUND

1. Field

This relates to a dishwasher, and more particularly, to a dishwasher which controls operation based on an amount of measured vibration.

2. Background

Dishwashers wash dishes using high-pressure wash fluid sprayed from nozzles. In general, dishwashers include a washing tub and a sump disposed at the bottom of the tub that contains wash fluid. Dishwashers typically perform a washing operation, a drain operation, a rinsing operation and a drying operation.

During the washing operation, wash fluid contained in the sump is transferred to nozzles by a washing pump and is then sprayed into the tub at high pressure to remove residue from dishes contained in the tub, and the residue is collected at the bottom of the tub. During a drain operation, the residue is filtered off by a filtering device, and waste wash fluid collected in the sump is discharged by continuously driving a drain pump for a predefined amount of time, such as, for example, the time taken to completely drain the sump. Since the time taken to drain the sump may vary based on, for example, the amount of food residue filtered out by the filtering device, it may be necessary to determine whether a drain operation is complete by driving a cleaning motor the predefined amount of time after the beginning of the operation of the drain pump and measuring the load of wash fluid in the sump.

However, by continuously driving the drain pump for a predefined amount of time, regardless of whether a drain operation is complete or not, such as, for example even after wash fluid in a sump is completely discharged, the drain pump may tick over, thereby increasing power consumption and causing a considerable amount of vibration and noise, and deterioration in the performance and durability of the drain pump. In addition, the driving of the cleaning motor may generate noise.

SUMMARY OF THE INVENTION

A dishwasher is provided which controls the operation of a drain device according to an amount of vibration in the drain device.

A dishwasher as embodied and broadly described herein may include a sump configured to contain wash fluid; a drain device configured to drain the sump; a vibration sensor configured to measure the amount of vibration generated by the drain device; and a controller configured to control the operation of the drain device based on the amount of vibration measured by the vibration sensor.

The controller may terminate the operation of the drain device if the amount of vibration measured by the vibration sensor exceeds a predefined level. The predefined vibration level may be set based on the vibration properties of the drain device, which may vary according to whether wash fluid exists in the sump.

Since the dishwasher controls the operation of the drain device based on an amount of vibration generated by the drain device, it is possible to reduce damage to the dishwasher caused by vibration.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of embodiments as broadly described herein will become more apparent by describing in detail embodiments with reference to the attached drawings in which:

FIG. 1 illustrates a cross-sectional view of a dishwasher according to an exemplary embodiment as broadly described herein;

FIG. 2 illustrates a perspective view of a sump of the dishwasher shown in FIG. 1;

FIG. 3 illustrates a block diagram of the dishwasher shown in FIG. 1;

FIG. 4 illustrates a flowchart of a driving method of the dishwasher shown in FIG. 1, according to an exemplary embodiment as broadly described herein; and

FIG. 5 illustrates a flowchart of a driving method of the dishwasher shown in FIG. 1, according to another exemplary embodiment as broadly described herein.

DETAILED DESCRIPTION

An exemplary embodiment of a dishwasher will hereinafter be described in detail with reference to FIGS. 1 through 3. FIG. 1 illustrates a cross-sectional view of a dishwasher 100 according to an exemplary embodiment as broadly described herein, FIG. 2 illustrates a perspective view of a sump 120 of the dishwasher shown in FIG. 1, and FIG. 3 illustrates a block diagram of the dishwasher 100.

The dishwasher 100 may include a tub 110, which serves as a washing tub for washing dishes and the like, a door (not shown) provided at the front of the tub 110, a sump 120 provided at a center of the bottom of the tub 110, and upper and lower racks 131 and 132 movably provided in the tub 110 so as to hold dishes and the like.

The dishwasher 100 may also include a washing pump 121, which pumps wash fluid out of the sump 120 at high pressure, a washing motor 122, which is disposed on one side of the washing pump 121 and drives the washing pump 121, a guide 126, which guides the wash fluid pumped by the washing pump 121, a lower nozzle 123, which is disposed above the sump 120 and sprays wash fluid up toward the lower rack 132, an upper nozzle 124, which is connected to the guide 126, is disposed below the upper rack 131, and sprays wash fluid up toward the upper rack 131, and a top nozzle 125, which is disposed near the ceiling of the tub 110 and sprays wash fluid downwardly toward the upper rack 131.

The dishwasher 100 may also include a drain device 140 provided on one side of the sump 120 to drain the sump 120. The drain device 140 may include a rotary drain pump 141 and a drain motor 142, which drives the drain pump 141. The drain motor 142 may be continuously driven until the sump 120 is completely drained. However, the drain device 140 is not restricted to that set forth herein. That is, various types of pumps may be used as the drain device 140.

Referring to FIGS. 2 and 3, the dishwasher 100 may also include a vibration sensor 150 provided on one side of the drain pump 141 to sense vibration caused by the operation of the drain pump 141, and a controller 160 which controls the operation of the drain pump 141. The controller 160 may also control the operation of the dishwasher 100.

During the operation of the drain pump 141, a predetermined amount of vibration may be generated. The amount of vibration caused by the drain pump 141 may vary according to whether or not wash fluid is present in the sump 120. That is, if wash fluid is present in the sump 120, the wash fluid may be continuously discharged through the drain pump 141, and thus, the amount of vibration and noise generated by the drain pump 141 may be negligible. However, if there is no wash fluid in the sump 120, the drain pump 141 may tick over, thus increasing the amount of vibration and noise generated by the drain pump 141.

The operation of the drain pump 141 may be terminated when the sump 120 is completely drained. If the drain pump 141 continues to be driven even after the sump 120 is completely drained, the drain pump 141 may tick over, thus causing a considerable amount of vibration and noise. This vibration and noise may cause user dissatisfaction, and may degrade the performance and durability of the drain pump 141. In addition, if the drain pump 141 ticks over, the power consumption of the dishwasher 100 may increase. Therefore, a drain operation may be performed based on the vibration properties of the drain pump 141, which may vary based on whether or not wash fluid is present in the sump 120, so that the operation of the drain pump 141 may be terminated when the sump 120 is completely drained.

More specifically, the controller 160 may terminate the operation of the drain pump 141 by turning off the drain motor 142 if the amount of vibration sensed by the vibration sensor 150 exceeds a predefined vibration level.

The predefined vibration level may correspond to an amount of vibration generated by the drain pump 142 when the sump 120 is completely drained, i.e., when a drain operation is complete. The predefined vibration level may be determined based on the vibration properties of the drain pump 141, which may vary according to whether or not wash fluid is present in the sump 120. More specifically, the predefined vibration level may be determined based on the amount of vibration generated when the drain pump 141 ticks over. That is, the drain pump 141 may be driven when no wash fluid is present in the sump 120, and the amount of vibration generated by the drain pump 141 may be measured. Since the amount of vibration generated by the drain pump 141 may vary based on the type of the drain pump 141 and the structure of the sump 120, the predefined vibration level may be set differently for different types of dishwashers.

As described above, the dishwasher 100 may terminate the operation of the drain pump 141 if the amount of vibration generated by the drain pump 141 exceeds the predefined vibration level. Thus, it is possible to precisely determine when a drain operation will be complete and to terminate the operation of the drain pump 141 when the drain operation is complete. Therefore, it is possible to prevent the drain pump 141 from being continuously driven when no wash fluid is present in the sump 120 and thus prevent noise and vibration from being generated due to the drain pump 141 ticking over. In addition, the dishwasher 100 does not need to drive the washing motor 122 to determine whether a drain operation is complete, thus reducing noise.

The predefined vibration level may be classified into a first vibration level and a second vibration level. The first vibration level may be set based on the vibration properties of the drain pump 141, and the second vibration level may be set based on the durability of the drain pump 141. The second vibration level may be higher than the first vibration level. More specifically, the first vibration level may be determined based on the amount of vibration generated by the drain pump 141 when no wash fluid is present in the sump 120. The second vibration level may be set lower than a critical amount of external vibration that may cause damage to the sump 120 or the drain pump 141. The first and second vibration levels may be altered according to the type of the drain pump 141 and the structure of the sump 120 and may be set differently for different types of dishwashers.

If the amount of vibration sensed by the vibration sensor 150 is between the first vibration level and the second vibration level, the controller 160 may reduce the rotation speed of the drain motor 142 and may thus reduce the operating speed of the drain pump 141. If a filter device (not shown) for filtering wash fluid or an inlet to the drain pump 141 is clogged with residue in the sump 120, wash fluid may not be able to properly flow into the drain pump 141. In this case, the amount of vibration measured by the vibration sensor 150 may exceed the first vibration level. However, the controller 160 may not readily terminate the operation of the drain pump 141. Instead, the controller 160 may continue to perform a drain operation by driving the drain pump 141 at a reduced speed so as to reduce vibration and noise. However, if the amount of vibration measured by the vibration sensor 150 exceeds the second vibration level, the durability of the sump 120 or the drain device 140 is highly likely to deteriorate, and thus, the controller 160 may immediately terminate the operation of the drain motor 142.

Referring to FIG. 3, the dishwasher 100 may also include an alarm device 170, which outputs an alarm message to a user if the amount of vibration measured by the vibration sensor 150 exceeds the predefined vibration level. When the amount of vibration measured by the vibration sensor 150 exceeds the predefined vibration level, it may be determined that a drain operation is complete or that wash fluid cannot be properly supplied into the drain pump 141. In this case, the alarm device 170 may transmit an alarm message to the user and may thus allow the user to examine whether a drain operation is being properly performed.

If the predefined vibration level is classified into the first and second vibration levels, the alarm device 170 may output an alarm message to the user only if the amount of vibration measured by the vibration sensor 150 exceeds the second vibration level. When the amount of vibration measured by the vibration sensor 150 exceeds the second vibration level, the durability of the dishwasher 100 is highly likely to deteriorate. Thus, it is necessary to terminate the operation of the drain pump 141 and then notify the user of the termination of the operation of the drain pump 141.

The alarm device 170 may include a display 105, which displays a message indicating whether the operation of the drain device 140 has been terminated abnormally, and a sound output device 175, which outputs a sound signal indicating whether the operation of the drain device 140 has been terminated abnormally. Alternatively, the alarm device 170 may include only one of the display 105 or the sound output device 175. In another alternative embodiment, the alarm device 170 may include both the display unit 105 and the sound output device 175, and only one of the display 105 and the sound output device 175 may be selected for use.

In order to notify the user whether the operation of the drain pump 141 has been terminated abnormally by the controller 160, the display 105 may display a text message or an icon or may turn on or off a lamp. For example, if the operation of the drain pump 141 is terminated because the amount of vibration sensed by the vibration sensor 150 exceeds the second vibration level, the display 105 may output a message stating “A washing operation has been terminated abnormally,” or may turn on or off a lamp. The controller 160 may control the display 105 to display a blinking text message.

The display 105 may account for part of a control panel (not shown), which controls the functions of the dishwasher 100 and displays the operating state of the dishwasher 100. For example, the display 105 may be a liquid crystal display (LCD) or a light-emitting diode (LED) disposed on one side of the control panel. The display unit 105 may not only indicate whether a washing operation has been terminated abnormally, but may also display a dishwashing program chosen by the user and the remaining operating time of the dishwasher 100. That is, the display 105 may include a region for displaying the remaining operating time of the dishwasher 100, a region for displaying a dishwashing program chosen by the user and the progress of the operation of the dishwasher 100, and a region for displaying a message indicating whether a drain operation is complete. However, other arrangements may also be appropriate. That is, the dishwasher 100 may also include an additional display unit for displaying a message indicating whether a drain operation is complete.

The sound output device 175 may output a voice message or a sound indicating that the operation of the dishwasher 100 has been terminated abnormally by the controller 160. For example, if a drain operation is terminated abnormally by the controller 160, the sound output device 175 may output a voice message saying “A washing operation has been terminated abnormally. Please make sure that a drain operation is being properly performed,” or may output a sound signal such as a buzzer sound. The sound output device 175 may be realized as a small-sized speaker (not shown) included in the dishwasher 100. By using the sound output device 175, it is possible to effectively notify the user when the operation of the dishwasher 100 has been terminated abnormally, even when the user is remote from the dishwasher 100.

The vibration sensor 150 may include various types of sensors such as, for example, a speedometer sensor, an accelerometer sensor, or a displacement sensor. In the exemplary embodiment of shown in FIGS. 1-3, the vibration sensor 150 may be configured using an accelerometer sensor. An accelerometer sensor includes a piezoelectric element and a mass element attached to the piezoelectric element to detect a variation in a current resulting from a variation in the pressure on the piezoelectric element upon the occurrence of external vibration. An accelerometer sensor is generally light-weighted and small-sized, is easy to implement and can provide wide measurement ranges and high precision.

The vibration sensor 150 may be disposed on one side of the drain pump 141 and may be fixed to the drain pump 141 by using, for example, bolts, magnets or an adhesive. More specifically, the vibration sensor 150 may be fixed to the case of the drain pump 141 by using bolts in order to provide wide measurement ranges. The position of the vibration sensor 150 is not restricted to that set forth herein. That is, the vibration sensor 150 may be placed at any location as long as the vibration sensor 150 can sense vibration generated by the drain device 140. For example, the vibration sensor 150 may be disposed on one side of the drain motor 142 or on one side of the sump 120, which is near the drain motor 142.

An operating method of the dishwasher 100 shown in FIG. 1 will hereinafter be described in detail with reference to FIGS. 3 and 4.

Referring to FIG. 4, when dishes are loaded in the tub 110, the controller 160 determines whether a request for the execution of the operation of the dishwasher 100 has been issued (S110). If it is determined that a request for the execution of the operation of the dishwasher 100 has been issued (S115), the controller 160 performs a washing operation according to a selected dishwashing program (S120). More specifically, when wash fluid is supplied into the sump 120, the controller 160 turns on the washing motor 122 and thus drives the washing pump 121. The wash fluid in the sump 120 is alternately pumped into the lower nozzle 123 and the guide 126 by the washing pump 121. The wash fluid pumped into the guide 126 is transferred to the upper nozzle 124 and the top nozzle 125 and is then sprayed into the tub 110 through the upper nozzle 124 and the top nozzle 125. In this manner, a washing operation is performed on the dishes loaded in the tub 110.

Once the washing operation is complete, waste wash fluid in the sump 120 is discharged by performing a drain operation (S130). More specifically, the controller 160 may turn on the drain motor 142 and may thus drive the drain pump 141 (S131). Once the drain pump 141 is driven, residue included in waste wash fluid collected in the sump 120 are filtered out by a filtering device (not shown), and the resulting wash fluid is discharged from the dishwasher 100 through the drain pump 141.

During the drain operation, the vibration sensor 150 continuously measures the amount of vibration generated by the drain pump 141 (S132). The controller 160 determines whether the amount of vibration measured by the vibration sensor 150 exceeds a predefined vibration level (S133). If the amount of vibration measured by the vibration sensor 150 exceeds the predefined vibration level, the controller 160 may terminate the operation of the drain pump 141, and thus, the drain operation may be complete.

Once the drain operation is complete, the controller 160 performs a subsequent operation (S140). More specifically, the controller 160 supplies clean wash fluid into the sump 120, and sequentially performs a rinsing operation for rinsing the dishes in the tub 110 and a drying operation for drying wet dishes. Then, the operating method of the dishwasher 100 is complete.

An operating method of the dishwasher 100 shown in FIG. 1, according to another exemplary embodiment will hereinafter be described in detail with reference to FIG. 5.

Referring to FIG. 5, the controller 160 determines whether a request has been issued (S210, S215), and performs a washing operation as appropriate (S220). The controller 160 then performs a drain operation (S230) and drives the drain pump 141 (S231). The vibration sensor 150 measures the amount of vibration generated by the drain pump 141 (S232). The controller 160 determines whether the amount of vibration measured by the vibration sensor 150 exceeds a first vibration level (S233).

If the amount of vibration measured by the vibration sensor 150 exceeds the first vibration level, the controller 160 may determine whether the amount of vibration measured by the vibration sensor 150 also exceeds a second vibration level (S234). If the amount of vibration measured by the vibration sensor 150 does not exceed the second vibration level, the controller 160 may reduce the operating speed of the drain pump 141, may drive the drain pump 141 at the reduced speed for a predetermined time, and may then terminate the operation of the drain pump 141 (S235). On the other hand, if the amount of vibration measured by the vibration sensor 150 also exceeds the second vibration level, the controller 160 may immediately terminate the operation of the drain pump 141 (S236).

Once the drain operation is complete, the controller 160 performs a subsequent operation (S240). More specifically, the controller 160 supplies clean wash fluid into the sump 120 and performs a rinsing operation for rinsing the dishes in the tub 110 and then a drying operation for drying wet dishes. Then, the operating method of the dishwasher 100 is complete.

Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” “certain embodiment,” “alternative embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment as broadly described herein. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various numerous variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. 

1. A dishwasher, comprising: a sump that receives wash fluid positioned below a tub; a drain device that drains the sump; a vibration sensor that measures an amount of vibration generated by the drain device; and a controller that controls operation of the drain device based on the amount of vibration measured by the vibration sensor.
 2. The dishwasher of claim 1, wherein the controller controls operation of the drain device based on the amount of vibration measured by the vibration sensor compared to a predefined vibration level.
 3. The dishwasher of claim 2, wherein the controller terminates operation of the drain device when the amount of vibration measured by the vibration sensor exceeds the predefined vibration level.
 4. The dishwasher of claim 2, wherein the predefined vibration level is set based on vibration properties of the drain device, wherein the vibration properties of the drain device vary based on whether wash fluid is present in the sump.
 5. The dishwasher of claim 2, wherein the predefined vibration level is set based on an amount of vibration generated by the drain device when the drain device ticks over.
 6. The dishwasher of claim 1, further comprising an alarm that outputs an alarm message when the amount of vibration measured by the vibration sensor exceeds a predefined vibration level.
 7. The dishwasher of claim 2, wherein the predefined vibration level comprises a first vibration level that is based on vibration properties of the drain device, which vary based on whether wash fluid is present in the sump, and a second vibration level that is based on durability of the sump, the second vibration level being higher than the first vibration level.
 8. The dishwasher of claim 7, wherein the controller reduces an operating speed of the drain device when the amount of vibration measured by the vibration sensor is greater than the first vibration level and is less than the second vibration level.
 9. The dishwasher of claim 7, further comprising an alarm that outputs an alarm message indicating abnormal operation of the dishwasher when the amount of vibration measured by the vibration sensor exceeds the second vibration level.
 10. The dishwasher of claim 7, wherein the controller terminates operation of the drain device when the amount of vibration measured by the vibration sensor exceeds the second vibration level.
 11. The dishwasher of claim 6, wherein the alarm comprises a display that generates a visual indicator of the alarm message.
 12. The dishwasher of claim 11, wherein the visual indicator comprises a text message, icon, or a lamp that is turned on or off.
 13. The dishwasher of claim 6, wherein the alarm comprises a sound output device that generates an audible indicator of the alarm message.
 14. The dishwasher of claim 13, wherein the audible indicator comprises a voice message or an alarm sound.
 15. The dishwasher of claim 11, further comprising a control panel that receives a manipulation signal related to control of the dishwasher and that displays information regarding operation of the dishwasher.
 16. The dishwasher of claim 15, wherein the display is provided with the control panel.
 17. The dishwasher of claim 1, wherein the vibration sensor is coupled to the drain device.
 18. The dishwasher of claim 1, wherein the vibration sensor comprises an accelerometer sensor. 